Weanling baboons were inoculated with 109–1010
B. pertussis D420 bacteria on Day 0. On day 3 after infection (indicated by arrow), animals in the treatment group (n=4) were administered hu1B7 and hu11E6 antibodies intravenously, while control animals (n=4) were given nothing. All animals were subsequently monitored for A, WBC count, B, bacteria recovered by nasopharyngeal wash and C, coughing on the days indicated. Groups shown include controls (solid black icons, dashed line, C1–C4), treated animals who were mildly colonized (grey icons, dotted black line, M1 and M2), and treated animals which were heavily colonized (hollow icons, solid grey line, H1 and H2). D, Serum anti-Fha titers for individual animals are shown to assess endogenous immune responses. Titers were normalized to the maximum response observed for serum from a historical control baboon, collected three weeks after experimental infection. Serum was not available for animal C3.